Gastein, Kaprun, Saalbach and the Grossglockner. 4 guides.

Bad Gastein built grand hotels vertically around falling waterBad Gastein was built as a spa town on radon-bearing thermal water and its grand hotels are terraced into a ravine with the falls running through the middle of them.
Kaprun reservoirs began in 1938 under forced labourThe Kaprun high-mountain reservoirs began in 1938 as a Nazi war project built with forced labour, and were finished after 1945.
Grossglockner Hochalpenstrasse closes every winter by permissionThe Grossglockner Hochalpenstrasse climbs to the Franz-Josefs-Höhe below Austria's highest peak. It was built in the 1930s, it is a toll road, and it closes for the winter — the point being that a mountain road is a decision that gets renewed every year.
Saalbach linked separate villages into one rideable loopSaalbach-Hinterglemm and its neighbours linked their networks into a circuit you can ride round in a day.